1. Field of the Invention
This invention relates to a transport system having a lift device for raising and lowering articles, and a moving body for moving the lift device.
More particularly, a transport container to be transported includes a main container body defining an opening for storing articles and having a support portion formed on an upper surface of the container body for suspending the container body, and a lid for closing the opening of the main container body. When the opening is closed by the lid, the interior space of the main container body is sealed. The invention relates to a transport system having a lift device for raising and lowering the transport container while suspending the transport container by holding the support portion thereof, and a moving body for moving the lift device.
2. Description of the Related Art
In the transport system having the above construction, articles such as semiconductor substrates that are vulnerable to dust are received in transport containers and transported free from adverse effects of dust. This transport system is used in manufacturing equipment for successively transporting the transport containers to a plurality of processing apparatus that perform various manufacturing processes to manufacture semiconductor substrates or the like. In such manufacturing equipment, the transport containers are placed on receiving surfaces in article loading and unloading stations of the above processing apparatus. When transporting the transport containers, the main container bodies are suspended by the support portions formed on the upper surfaces thereof, raised and lowered, and transported horizontally as necessary.
In such a transport system, conventionally, when transporting the transport containers, each container is suspended by the support portion formed on the upper surface of the main container body continuously from start till end of the transport (see to Japanese Patent Publication (Unexamined) H9-77455).
In the above conventional construction, the transport container may, for example, vibrate up and down during transport. However, since the transport container is supported as gripped and suspended by the support portion formed on the upper surface, the vertical vibration occurring in time of transport causes a dynamic load of articles stored in the main container body. As a result, the transport container is deformed to enlarge the capacity of interior space of the main container body, whereby ambient air could enter the interior space of the main container body through sealed portions between the lid and the main container body. The transport container for storing articles such as semiconductor substrates are often formed of plastic. Such main container body formed of plastic is deformable by the vertical vibration occurring in time of transport, to enlarge the capacity of interior space of the main container body and allow entry of ambient air. Thus, the articles may undergo adverse effects such as lowering of quality.